AT_BASE_PLATFORM in AUXV is absent on kernels available on Ubuntu 17.10
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
The Ubuntu-power-systems project |
Fix Released
|
Medium
|
Canonical Kernel Team | ||
linux (Ubuntu) |
Fix Released
|
Medium
|
Unassigned | ||
Artful |
Fix Released
|
Medium
|
Unassigned | ||
Bionic |
Fix Released
|
Medium
|
Unassigned |
Bug Description
== SRU Justification ==
AT_BASE_PLATFORM in AIXV is not exported to userspace on P9 baremetal machines
causing trouble to userspace tools and software that rely on that information,
notably operf and opreport (from oprofile 1.2.0+) will refuse to run without
that information.
This bug is fixed by commit e4b79900222b, which is in linux-next and just
landed in mainline, but is not contained in any release as of yet.
== Fix ==
e4b79900222b ("powerpc/64s: Fix NULL AT_BASE_PLATFORM when using DT CPU features")
== Regression Potential ==
Low. Limited to powerpc.
== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.
---Problem Description---
AT_BASE_PLATFORM in AUXV is absent on kernels available on Ubuntu 17.10
---Additional Hardware Info---
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 176
On-line CPU(s) list: 0-175
Thread(s) per core: 4
Core(s) per socket: 22
Socket(s): 2
NUMA node(s): 8
Model: 2.2 (pvr 004e 1202)
Model name: POWER9, altivec supported
CPU max MHz: 2800.0000
CPU min MHz: 2300.0000
L1d cache: 32K
L1i cache: 32K
L2 cache: 512K
L3 cache: 10240K
NUMA node0 CPU(s): 0-87
NUMA node8 CPU(s): 88-175
NUMA node250 CPU(s):
NUMA node251 CPU(s):
NUMA node252 CPU(s):
NUMA node253 CPU(s):
NUMA node254 CPU(s):
NUMA node255 CPU(s):
Machine Type = P9, DD2.2, Witherspoon, baremetal
---Steps to Reproduce---
AT_BASE_PLATFORM in AIXV is not exported to userspace on P9 baremetal machines causing trouble to userspace tools and software that relie on that information, notably operf and opreport (from oprofile 1.2.0+) will refuse to run without that information show a error message like:
gromero@
NULL returned for one or both of AT_PLATFORM/
AT_PLATFORM: power9; AT_BASE_PLATFORM: (null)
Unable to obtain cpu_type
Verify that a pre-1.0 version of OProfile is not in use.
If the /dev/oprofile/
installation, and use its 'opcontrol' command, passing the --deinit option.
Unable to ascertain cpu type. Exiting.
---uname output---
linux-image-
Userspace tool common name: operf, opreport
Dear maintainer. please consider applying the following fix that's already available upstream:
Thank you.
tags: | added: architecture-ppc64le bugnameltc-166086 severity-medium targetmilestone-inin1710 |
Changed in ubuntu: | |
assignee: | nobody → Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) |
affects: | ubuntu → linux (Ubuntu) |
Changed in ubuntu-power-systems: | |
importance: | Undecided → Medium |
status: | New → Triaged |
assignee: | nobody → Canonical Kernel Team (canonical-kernel-team) |
tags: | added: triage-g |
Changed in linux (Ubuntu): | |
status: | New → Triaged |
importance: | Undecided → Medium |
Changed in linux (Ubuntu Artful): | |
importance: | Undecided → Medium |
status: | New → Triaged |
assignee: | nobody → Joseph Salisbury (jsalisbury) |
Changed in linux (Ubuntu): | |
assignee: | Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) → Joseph Salisbury (jsalisbury) |
Changed in linux (Ubuntu Artful): | |
status: | Triaged → In Progress |
Changed in linux (Ubuntu): | |
status: | Triaged → In Progress |
Changed in ubuntu-power-systems: | |
status: | Triaged → In Progress |
Changed in linux (Ubuntu Bionic): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Artful): | |
status: | In Progress → Fix Committed |
Changed in ubuntu-power-systems: | |
status: | In Progress → Fix Committed |
Changed in ubuntu-power-systems: | |
status: | Fix Committed → Fix Released |
I built a test kernel with commit e4b79900222b8cc cd4da4a7a89581f from linux-next. The test kernel can be downloaded from: kernel. ubuntu. com/~jsalisbury /lp1759312
http://
Can you test this kernel and see if it resolves this bug?
Note, to test this kernel, you need to install both the linux-image and linux-image-extra .deb packages.
Thanks in advance!